Han Xu, Li Kaixin, Shao Qi, Zhang Wenjing, Li Tian, Gao Yuan, Feng Peizhong, Lv Zhe, Ling Yihan
School of Physics, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, China.
Heilongjiang Provincial Key Laboratory of Advanced Quantum Functional Materials and Sensor Components, Harbin, Heilongjiang, 150001, China.
Adv Mater. 2025 Jul;37(28):e2502068. doi: 10.1002/adma.202502068. Epub 2025 May 2.
One challenge to realize the commercialization of solid oxide cell technology is the instability and poor catalytic activity of the oxygen electrode during stack operation caused by Cr-containing alloy interconnect. Particularly well-known Sr/Ba-containing perovskite oxides can easily segregate Sr/Ba to the surface, reacting with vaporized Cr and causing Cr poisoning. To address this challenge, this work designs an entropy-driven layered structural strategy to suppress the surface segregation of cations and realize substantial enhancement of catalysis activity and Cr tolerance. The investigations suggest that the planar strain generated by entropy increase in the rare earth layer plays a pivotal role in suppressing alkaline earth segregation. Consequently, the half-cells with (LaPrNdSm)BaSrCoFeO (LPNSBSCF) oxygen electrode exhibit significantly improved stability in various operation conditions with Cr containment. Furthermore, LPNSBSCF shows the high power density of 2.12 W cm at 800 °C and 1.41 W cm at 650 °C in the single cells of oxygen ion and proton type, respectively. This paper provides new insights into segregation suppression in layered perovskite and offers theoretical guidance for the rational design of oxygen electrodes to achieve high Cr-tolerance and catalytic activity.
实现固体氧化物电池技术商业化面临的一个挑战是，在电池堆运行过程中，含铬合金互连会导致氧电极不稳定且催化活性差。特别著名的含锶/钡的钙钛矿氧化物很容易将锶/钡偏析到表面，与蒸发的铬发生反应，导致铬中毒。为应对这一挑战，本研究设计了一种熵驱动的层状结构策略，以抑制阳离子的表面偏析，并大幅提高催化活性和耐铬性。研究表明，稀土层中熵增加产生的平面应变在抑制碱土金属偏析方面起着关键作用。因此，具有(LaPrNdSm)BaSrCoFeO(LPNSBSCF)氧电极的半电池在含铬的各种运行条件下表现出显著提高的稳定性。此外，LPNSBSCF在氧离子型和质子型单电池中，分别在800℃时显示出2.12W/cm²的高功率密度，在650℃时显示出1.41W/cm²的高功率密度。本文为层状钙钛矿中的偏析抑制提供了新的见解，并为合理设计高耐铬性和催化活性的氧电极提供了理论指导。
